It is in earlier stages vs Dynamo for Revit but there is a community here - simply click on the Civil3d tag on your thread and you’re there! Be sure to check out Camber as well as this has a lot of tools/resources in there:
The true ‘demand’ for Dynamo for C3D comes from your employer ultimately, it’s up to us as automators to find the value in what it can do and sell it to the place we work so we can begin to build a culture of automation/computation there.